We made a mistake! ms35 is allelic to ms23,
but what is the correct map location?--Trimnell, MR, Fox, TW, Albertsen, MC
During conducting some cytology work in our lab, Shannon Stenejhem found
a reference in a 1985 MNL article written by DP West and MC Albertsen (MNL
59:87) that ms23 was allelic to a male-sterile mutant designated
ms*-Bear7 by the late Earl Patterson and who later designated it
as ms*-6011 (MNL 69:126-128). In 1999, we identified ms*-6011
as being a new male-sterile mutant, and we designated it as ms35
(MNL 73:49-50). For whatever reason, we did not consider all the available
information when we gave it the ms35 designation. One of the reasons
this may have occurred is that ms23 had been reported to be located
on chromosome 3L (MNL 62:71); whereas ms35 had been reported to
be located on chromosome 9L (MNL 69:126-128).

We decided that we should first find out if the 1985 allele test data
was correct. We made test-crosses between ms23 and ms35 in
the summer of 1999 and grew the progeny in the 1999 Hawaii winter nursery.
The two male-sterile mutants were found to be allelic (data shown below):

Female

Male

Progeny

X2(1:1, P>0.050=3.84)

ms23 Hom

ms35 Het

19 Fertiles

20 Steriles

0.03

ms35 Hom

ms23 Het

18 Fertiles

16 Steriles

0.12

We then planted the original ms35 seed that Earl gave us and
test-crossed it to both ms23 and the later developed ms35
material, to make sure seed stocks had not been "mixed up". These were
grown in our 2001 Johnston, IA, nursery and also were found to be allelic
(data shown below):

Female

Male

Progeny

X2(1:1, P>0.050=3.84)

ms35-Bear7 Hom

ms23 Het

13 Fertiles

25 Steriles

3.79

ms23 Hom

ms35-Bear7 Het

23 Fertiles

15 Steriles

1.68

ms35 Hom

ms35-Bear7 Het

21 Fertiles

23 Steriles

0.09

In the 1999 Hawaii winter nursery, we grew an F2 that had been constructed
to chromosome arm map ms35 by using SSR markers. We wanted to compare
the SSR-derived map location with the B-A translocation-derived map locations
previously assigned to ms23 and ms35. Leaf punches were taken
from 24 male-sterile plants and from 24 male-fertile plants for DNA isolation.
96 SSR markers, dispersed throughout the genome, were used to genotype
this family. No linkage was found with any markers on chromosome 3 or on
chromosome 9. Because of this conflicting data, we are now preparing to
re-map ms23 with other SSR markers in the hopes of determining the
correct map location.

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